The 2008 Christmas Number One is naturally Hallelujah by X-Factor winner Alexandra Burke. The single was released online at midnight last Sunday, just a few hours after her victory was announced on TV, and physically to what is left of the shops on Wednesday. It would have taken an event of seismic proportions to prevent the single outselling anything else in the market and with none appearing, her status as the best-selling singles act of the week was all but assured by the end of Monday.

Burke is the fourth X Factor winner in succession to see her single monopolise the seasonal listings, but the first week sales of the winners singles have been on a downward trend during that period. In 2005 Shayne Ward sold 742,180 copies of That's My Goal. Leona Lewis was down to 571,253 copies of A Moment Like This a year later, but last year's winner Leon Jackson saw his single When You Believe represent a sudden shrinking of their appeal, flying out of the shops to the tune of a "mere" 275,742. Alexandra Burke by contrast sold around 576,000 copies last week, the highest single-week sale of any single since Shayne Ward's three-quarters of a million three years ago and the fourth highest total of the 21st century. To put the sale in context, that is more than the rest of the Top 20 singles put together.

Alexandra Burke has. almost needless to say, surpassed her mother in terms of chart success. Hailed as the brightest soul talent of her era when she first emerged in the early 1990s, Melissa Bell never quite translated acclaim that into chart hits. Her only hit single of any kind came in November 1993 when her uncredited vocal on Soul II Soul's Wish helped it to a Number 24 peak.

Now originally the whole thrust of the discussion over Hallelujah was to evoke the same conversation we had a fortnight ago over Leona Lewis' rendition of Run - namely that your view of the record itself was largely dependent on how you felt about the other more definitive version of the song. It is a debate that we actually don't need to have, for the point of reference this week lies just one place below her in the sales rankings.

After entering the Top 40 for the first time ever last week at Number 30, Jeff Buckley's 1994 version of Hallelujah this week took on a life of its own, rocketing up the sales listings almost in sympathy with the brand new version. Whilst the finger will be pointed at the usual smattering of Facebook groups that suggested a coordinated campaign, I'm more inclined to credit public good taste and the sheer power of the song to capture the hearts of people who may only have become aware of it due to the X Factor version. After a sales duel with the Leona Lewis single that lasted for pretty much the entire week, Buckley's single finally edged ahead at the weekend to sensationally, and dare I say it, joyfully rest at Number 2.

Having two different versions of the same song in the Top 10 whilst rare is actually not totally unheard of. Commonplace in the very early (pre-rock n' roll) years of the charts, when it was normal for several popular singers to release versions of the most popular song of the moment, the phenomenon has also occurred at regular intervals in the modern era - and most particularly it seems at Christmas time. So it was that the seasonal chart of 1987 saw both Rick Astley and Nat King Cole duelling it out with competing versions of When I Fall In Love whilst in 1995 Oasis' original version of Wonderwall was swiftly joined in the Christmas Top 10 by an easy listening cover by Mike Flowers Pops. Outside of the festive season, you can study the charts from October 1987 to find both Steve Walsh and The Fatback Band in the bestsellers with I Found Lovin' whilst in early 1996 both Mark Snow and DJ Dado were on the chart with their own versions of The X-Files Theme.

For both versions to be in the Top 3 is rather more unusual, and indeed this weeks chart is quite historic, marking the first time since 1957 that two different versions of the same song are at Number 1 and Number 2 on the singles chart together. Simultaneous Top 3 versions have happened slightly more recently than that - notably in January 1965 when The Righteous Brothers were at Number 2 (on their way to the top) and Cilla Black was at Number 3 with competing versions of You've Lost That Lovin' Feeling. Note that these placings are taken from the Record Retailer chart that is regarded by the OCC and all the chart books as canon but which wasn't necessarily the most publicly visible countdown - thus it is entirely possible that alternative listings of the time did indeed show the two songs at 1 and 2.

You know there has to be a further twist, and so there is. Sneaking into the Top 40 at Number 36 from absolutely nowhere is the original version, written and recorded by Leonard Cohen for his 1984 album Various Positions. Extraordinary it is his first ever singles chart appearance in this country. Those paying close attention will note that the Cohen version bears minimal resemblance lyrically to both the Buckley and Burke versions. Part of the appeal of the song (and one of the reasons behind the 170 and counting different versions recorded by various acts) is that it has a variety of different verses, covering several different themes and which can be rearranged and reconfigured to taste. Cohen's original studio version was more spiritual in nature, alluding to many Old Testament stories whilst Jeff Buckley (copying from an earlier interpretation by John Cale) reworked the song as an ode to sexuality.

Part of the fun of anticipating the eventual X Factor winners rendition of the song was speculating just which verses would be included, and sure enough Alexandra Burke's version is a very much toned down version of the song, omitting some of its naughtier moments and thus recasting the song as an uplifting tale of personal redemption. Produced, like all X Factor songs, as a bombastic power ballad building to an epic crescendo, it may not be to everyone's taste but you can hardly criticise a song which is built to be whatever the singer wants it to be, and with two other versions selling alongside it in tandem, the tastes of all appear to be neatly served by the ultimate chart success of this most extraordinary of compositions.

As well as being Leonard Cohen's first ever chart single, Hallelujah has instantly become his most successful composition. Countless artists have recorded his songs over the years but few have become widespread commercial hits. Jennifer Warnes reached Number 74 with First We Take Manhatten in 1987, Bird On A Wire hit Number 70 for the Neville Brothers in 1990 but until today the highest charting Cohen song was Ian McCulloch's take on Lover Lover Lover which reached Number 47 in early 1992.

My final take on this topic is this: The battle of the Hallelujahs has generated comment, discussion of and publicity for the singles chart in a manner that hasn't been seen for a great many years. Not since the start of the decade has the race for Number One and the potential chart performance of a single been the subject of so much mainstream attention. For all the talk of X Factor rendering the race for Christmas Number One almost meaningless, the Christmas chart of 2008 will go down as one of the most talked about, most referenced and dare I say it most fondly remembered countdowns of the 21st century so far. Hallelujah.

Just one other new single of note was released this week. Never unafraid to milk a concept to death, comedian Peter Kay follows up The Winners Song with a second single in character as "Britain's Got The Pop Factor Winner" Geraldine McQueen. Once Upon A Christmas Song is once again a satire that is just a little too familiar to work effectively, a singalong Christmas record about Christmas records that are played every year and with which everyone is familiar. Presumably part of the aim was to see if the concept could eat itself and the track become a seasonal perennial, but despite this creditable Number 5 entry (arriving on the back of much publicity from Channel 4, who repeated the original "Pop Factor" sitcom last week) you suspect the record is something of a passing novelty. At the risk of being mean-spirited, is it out of order to note that despite appearing in the video as Geraldine McQueen, Kay doesn't actually sing the song in character but uses his own voice, and indeed the sleeve credits the single to "Peter Kay's Geraldine McQueen", just in case we were unaware of the alter-ego of the transsexual Irishwoman.

The Number One single wasn't the only direct consequence of the X Factor final last weekend. Beyonce is the act who has the honour of two singles in the seasonal Top 10, but accompanying If I Were A Boy (itself rebounding to Number 4) is not, as you might expect Single Ladies (Put A Ring On It) (which climbs to Number 20 this week), but something else from her own catalogue. Listen had already returned to the chart following its performance by Alexandra Burke on the TV show earlier in the competition, but it was her reprise of the song in a memorable duet with the lady herself that finally lit a fire under the track. As a result the 'Dreamgirls' song rockets to Number 8 to become the second of two spontaneous hit singles in the Top 10. First released in early 2007, the single struggled in competition with Irreplaceable which was still selling in respectable quantities and so underperformed somewhat, eventually stuttering to Number 16. Arguably underappreciated at the time, Listen finally becomes the smash hit it was always destined to be. [And it is worth preserving here not the original video, but the jaw-dropping Burke/Beyonce duet which prompted this chart run. It still brings tears to my eyes to watch it. And this was the moment which won her the contest].

Finally, for this festive chart, I'm tempted to note with some satisfaction that the top-selling singles are dominated by contemporary hits with relatively few incursions by the festive oldies. Just for once the bookmakers called it correctly, with Fairytale Of New York ending up as the biggest selling classic for the second year running, peaking at Number 12. Last year's runner-up follows suit, All I Want For Christmas Is You actually slumps slightly, down at Number 17. It is a far cry from last year when both made it to the Christmas Top 10 and the Top 40 as a whole was almost swamped with seasonal favourites. Whilst it must be noted that due to Christmas Day falling so late in the week this year this chart covers sales only up to Saturday 20th and so the potential exists for festive favourites to gain momentum in the run up to the big day itself, I'm tempted to suggest that the 2007 peaks were a one-off and that future years will see ever diminishing appearances for digital sales of the festive classics.

So that was the Christmas chart for 2008. Many thanks to all correspondents, commenters, downloaders and readers for all your support this last year and I hope you have a very enjoyable holiday. This is the 17th Christmas chart I've had the privilege of writing about online, and I can honestly say it has been my favourite one so far. Merry Christmas.